In a factory having a plurality of machine tools, such as machining centers, each provided with an automatic tool changer and an NC device, a plurality of tools are typically stored in a toolroom as well as in the tool magazines of the respective machine tools. For example, JP-A-2007-125642, also filed by the applicant of the present application, describes a tool changer for changing tools automatically between a spindle of a machine tool and a tool magazine storing a plurality of tools. The JP publication is incorporated by reference. In order manage such a plurality of tools, a tool number is allocated to each of the tools prepared in a factory. A database stores tool data, such as the types, the lengths and the diameters of tools by associating them with the tool numbers.
Machine tools, such as machining centers, are controlled in accordance with an NC program which describes machining processes. A tool, necessary for a machining process described in a machining program, is selected by a tool magazine and supplied to the machine tool by an automatic tool changer. Therefore, a tool magazine must store all of the tools necessary to execute an NC program. In a tool magazine, each of the tools is fitted with a tool pot having a unique number allocated thereto. A tool magazine has a tool magazine database storing the data, relative to all of the tools in the tool magazine, by associating with the tool pot numbers.
A CAM operator creates an NC program by using a CAM system, based on CAD data creased by a designer of a workpiece, for producing the workpiece. The tools (necessary tool), necessary to execute the respective machining processes described in the NC program, are indicated in the NC program by using the tool numbers. JP-A-2004-142025, also filed by the applicant of the present application, shows an example of an NC program describing such tool numbers. This JP publication is incorporated by reference. When an NC program is changed, the operator of the machine tool must replace the tools in the tool magazine as per the changed NC program. This work is manually carried out by the operator. The operator of the machine tool prepares tools, necessary to execute the respective machining processes, in the tool magazine with reference to the tool numbers in the NC program. The operator fits the tools in tool pots having appropriate pot numbers, and revises the tool magazine data base so that both the tool numbers in the NC program and the pot numbers in the tool magazine database referring to the same tools.
For example, JP-A-H05-274023 describes a CNC device which is provided with a tool data table, storing tool data relative to the respective tools stored in a tool magazine, analyzes a machining program, and determines whether or not the tool data table stores tool data relative to a tool designated in the machining program, whereby if not, failure of tool is judged. The CNC device described in JP-A-H05-274023 allows an operator of a machine tool to easily determine whether or not the tool magazine stores the tools necessary to execute an NC program. However, there is a problem that according to the CNC device of JP-A-H05-274023, while it is possible to determine whether or not the necessary tool is stored in a tool magazine, it is not possible to determine as to which tool pot the tool is fitted in the tool magazine. Further, when a necessary tool is not stored in the tool magazine, it is difficult to find the tool in a storage facility, such as a toolroom.